YCanvas is a library that provides Stage3D (GPU) engine for perfectly overlapping grid based zooming projects like world maps or onBoard or simply a tile maps renderer. The engine is optimized for rendering speed as well as for relasing unused system resources.

While GPU API for Flash player requires textures at width and height at power of two, you can reach the best performance when using 256×256 or 512×512 source images etc.

Sample

package sk.yoz.ycanvas.demo.simple
{
    import flash.display.Sprite;
    import flash.display.StageAlign;
    import flash.display.StageScaleMode;
    import flash.events.Event;
    import flash.events.MouseEvent;
    import flash.geom.Point;
    import flash.geom.Rectangle;

    import sk.yoz.ycanvas.interfaces.IPartition;
    import sk.yoz.ycanvas.stage3D.YCanvasStage3D;
    import sk.yoz.ycanvas.utils.ILayerUtils;
    import sk.yoz.ycanvas.utils.IPartitionUtils;
    import sk.yoz.ycanvas.utils.TransformationUtils;

    [SWF(frameRate="60", backgroundColor="#ffffff")]
    public class ApplicationDemo extends Sprite
    {
        private var canvas:YCanvasStage3D;
        private var position:Point;

        public function ApplicationDemo()
        {
            stage.align = StageAlign.TOP_LEFT;
            stage.scaleMode = StageScaleMode.NO_SCALE;

            canvas = new YCanvasStage3D(stage, stage.stage3Ds[0], viewPort, canvasInit);
            canvas.partitionFactory = new PartitionFactory;
            canvas.layerFactory = new LayerFactory(canvas.partitionFactory);
        }

        private function get viewPort():Rectangle
        {
            return new Rectangle(0, 0, stage.stageWidth, stage.stageHeight);
        }

        private function canvasInit():void
        {
            canvas.center = new Point(35e6, 25e6);
            canvas.scale = 1 / 16384;
            render();

            stage.addEventListener(Event.RESIZE, onStageResize);
            stage.addEventListener(MouseEvent.MOUSE_DOWN, onMouseDown);
            stage.addEventListener(MouseEvent.MOUSE_WHEEL, onMouseWheel);
        }

        private function render():void
        {
            canvas.render();
            IPartitionUtils.disposeInvisible(canvas);
            ILayerUtils.disposeEmpty(canvas);

            var main:Layer = canvas.layers[canvas.layers.length - 1] as Layer;
            for each(var layer:Layer in canvas.layers)
                (layer == main) ? startLoading(layer) : stopLoading(layer);
        }

        private function startLoading(layer:Layer):void
        {
            var partition:Partition;
            var list:Vector. = layer.partitions;
            for(var i:uint = 0, length:uint = list.length; i < length; i++)
            {
                partition = list[i] as Partition;
                if(!partition.loading && !partition.loaded)
                    partition.load();
            }
        }

        private function stopLoading(layer:Layer):void
        {
            var partition:Partition;
            var list:Vector. = layer.partitions;
            for(var i:uint = 0, length:uint = list.length; i < length; i++)             {                 partition = list[i] as Partition;                 if(partition.loading)                     partition.stopLoading();             }         }                  private function onStageResize(event:Event):void         {             canvas.viewPort = viewPort;             render();         }                  private function onMouseDown(event:MouseEvent):void         {             stage.addEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);             stage.addEventListener(MouseEvent.MOUSE_UP, onMouseUp);             position = canvas.globalToCanvas(new Point(stage.mouseX, stage.mouseY));         }                  private function onMouseMove(event:MouseEvent):void         {             var current:Point = canvas.globalToCanvas(new Point(stage.mouseX, stage.mouseY));             var center:Point = new Point(                 canvas.center.x - current.x + position.x,                  canvas.center.y - current.y + position.y);             TransformationUtils.moveTo(canvas, center);             position = canvas.globalToCanvas(new Point(stage.mouseX, stage.mouseY));             render();         }                  private function onMouseUp(event:MouseEvent):void         {             stage.removeEventListener(MouseEvent.MOUSE_MOVE, onMouseMove);             stage.removeEventListener(MouseEvent.MOUSE_UP, onMouseUp);         }                  private function onMouseWheel(event:MouseEvent):void         {             TransformationUtils.scaleTo(canvas,                  canvas.scale * (event.delta > 0 ? 1.5 : 0.7), 
                canvas.globalToCanvas(new Point(stage.mouseX, stage.mouseY)));
            render();
        }
    }
}